class ExchangeUser {
  final String id;
  final String nickname;
  final String? avatar;

  ExchangeUser({
    required this.id,
    required this.nickname,
    this.avatar,
  });

  factory ExchangeUser.fromJson(Map<String, dynamic> json) {
    return ExchangeUser(
      id: json['id'] as String,
      nickname: json['nickname'] as String,
      avatar: json['avatar'] as String?,
    );
  }

  Map<String, dynamic> toJson() {
    return {
      'id': id,
      'nickname': nickname,
      'avatar': avatar,
    };
  }
} 